Fire alarm



FIG. 1 is a top plan view of a fire alarm embodying our new design.

FIG. 2 is a side elevational view thereof.

FIG. 3 is a left end elevational view thereof.

FIG. 4 is a right end elevational view thereof.

FIG. 5 is a bottom plan view thereof. 

We claim the ornamental design for a fire alarm, as shown. 